{{Short description|Species of shrub}} {{stack begin}} {{Speciesbox | image = Starr_010820-0009_Carissa_macrocarpa.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 20 November 2021">{{cite iucn |author=Botanic Gardens Conservation International (BGCI). |author2=IUCN SSC Global Tree Specialist Group |date=2019 |title=''Carissa macrocarpa'' |volume=2019 |article-number=e.T149504239A149504241 |doi=10.2305/IUCN.UK.2019-2.RLTS.T149504239A149504241.en |access-date=20 November 2021}}</ref> | genus = Carissa | species = macrocarpa | authority = (Eckl.) A.DC. | synonyms = ''Carissa grandiflora'' <small>(E.Mey.) A.DC.</small> }} {{nutritional value | name=Carissa, (natal-plum), raw | water=84.17 g | kJ=259 | protein=0.5 g | fat=1.3 g | carbs=13.63 g | calcium_mg=11 | iron_mg=1.31 | magnesium_mg=16 | phosphorus_mg=7 | potassium_mg=260 | sodium_mg=3 | vitC_mg=38 | thiamin_mg=0.04 | riboflavin_mg=0.06 | niacin_mg=0.2 | source_usda = 1 | note=[https://web.archive.org/web/20160309022617/https://ndb.nal.usda.gov/ndb/search/list?qlookup=09061&format=Full Link to USDA Database entry] }} {{stack end}}

'''''Carissa macrocarpa''''' is a shrub native to tropical and southern Africa. It is commonly known as the '''Natal plum''', '''amathungulu''',<ref name=EOL>{{Cite EOL |id=488417 |title=''Carissa macrocarpa'' |access-date=10 March 2025}}</ref> '''big num-num''' or '''large num-num'''.<ref name=EPPO>{{cite web |title=''Carissa macrocarpa'' |url=https://gd.eppo.int/taxon/CISMA |publisher=European and Mediterranean Plant Protection Organization (EPPO) |access-date=10 March 2025}}</ref>

''Carissa macrocarpa'' deals well with salt-laden winds, making it a good choice for coastal areas. It is commonly found in the coastal bush of the Eastern Cape and Natal.<ref name="Sparrow">Sparrow, Jacqueline and Gil Hanly. (2002), ''Subtropical Plants: A Practical Gardening Guide'', Portland, OR: Timber Press, Inc.</ref> It produces shiny, deep green leaves and snowy white flowers whose perfumed scent intensifies at night. Like other ''Carissa'' species, ''C. macrocarpa'' is a spiny, evergreen shrub containing latex. They bloom for months at a time. The ornamental plump, round, crimson fruit appears in summer and fall (autumn) at the same time as the blooms. In moderate, coastal areas the fruits appear through the year. The fruit can be eaten out of hand or made into pies, jams, jellies, and sauces.<ref name="Sparrow" /> Some claim that other than the fruit, the plant is poisonous.<ref>{{Cite news|url=http://www.floridata.com/ref/C/cari_mac.cfm|title=Carissa macrocarpa Plant Profile|access-date=2017-08-07}}</ref> However, this claim is a myth, possibly based on similarities to other plants with milky sap.<ref name="Carissa macrocarpa (University of Pretoria)">{{cite web|title=Carissa macrocarpa (Eckl.) A.DC.|url=http://web.up.ac.za/default.asp?ipkCategoryID=19374&subid=19374|website=University of Pretoria| date=28 June 2012 |access-date=5 October 2017|archive-url=https://web.archive.org/web/20140908091743/http://web.up.ac.za/default.asp?ipkCategoryID=19374&subid=19374|archive-date=September 8, 2014}}</ref> The College of Agricultural and Environmental Sciences at University of California, Davis rates the plant as mildly toxic.<ref name="CPCS">{{Cite web|url=http://ucanr.edu/sites/poisonous_safe_plants/Toxic_Plants_by_Scientific_Name_685/|title=Toxic Plants|last=Resources|first=University of California Agriculture and Natural|website=ucanr.edu|language=en-US|access-date=2017-08-07}}</ref> It appears in the South African National tree list as number 640.3.

A traditional food plant in Africa, this little-known fruit has potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.<ref name="Lost" />

==Taxonomy== Danish naturalist Christian Friedrich Ecklon described the Natal plum.

== Distribution == ''Carissa macrocarpa'' grows mainly in coastal areas of South Africa. It can be found on sand dunes and on the edges of coastal forests in the Eastern Cape and northwards to Natal and Mozambique. The species also occurs in Zambia and Zimbabwe and further north in the Democratic Republic of the Congo and Kenya.<ref name="iucn status 20 November 2021" /> Today the plant is also growing commonly in southern Florida and is cultivated in southern California and used widely as an ornamental in Hawaii, Central America and the Caribbean.<ref name="Lost">{{cite book |author=National Research Council |title=Lost Crops of Africa: Volume III: Fruits |url=http://books.nap.edu/openbook.php?record_id=11879 |access-date=2008-07-15 |volume=3 |date=2008-01-25 |publisher=National Academies Press |isbn=978-0-309-10596-5 |chapter=Carissa |chapter-url=http://books.nap.edu/openbook.php?record_id=11879&page=76 }}</ref>

== Horticultural aspects == thumb|left|{{center|Natal plum shrub}}

=== Propagation === ''Carissa macrocarpa'' is quite easy to grow. Its seeds germinate two to four weeks after sowing. The development of the seedlings is very slow at first. Plants cultivated from seeds bear fruits within the first two years. A vegetative propagation is possible and preferred. The most efficient method consists of notching young branchlets by cutting them halfway through. Then they are bent downwards and allowed to hang limply. After the young branchlets have built a callus, in approximately two months, the cutting has to be removed from the parent and planted in sand under moderate shade. Roots form within one month. ''Carissa macrocarpa'' will produce fruit within two years of applying this reproduction method.<ref name="Lost" />

=== Fertilizing === The maintenance of ''Carissa macrocarpa'' is simple. The plant is indigenous to South Africa and does not need fertilizer.{{Citation needed|date=October 2017}}

=== Pollination === thumb|right|Close-up of flower In the homeland of ''Carissa macrocarpa'' night-flying insects pollinates the white, bisexual flowers. Out of its origin area unfruitfulness has been attributed to inadequate pollination. However, hand pollination is possible and in future poor pollination could be avoided by cultivation of floral structures that are highly favourable for self-fertilization.<ref name="Lost" />

=== Orchard design === Narrow hedges are recommended as orchard design for ''Carissa macrocarpa'' due to its prickles. Like this the access to the fruits which are growing on the top of the bush is much simpler. Pruning the plant is beneficial because it induces the development of more fruiting tips. Beyond cutting, little pruning work has to be done to restrain the bush from massive growth. This results in an increasing amount of fruits per plant.<ref name="Lost" />

=== Harvesting === thumb|right|200px|Longitudinal section of a ripe fruit With a minimal yield of 3 tons per hectare under commercial production in South Africa, the productivity is considered as high. The main fruit production is in summer with slightly varying ripening times. So each fruit must be picked when it is ripe. Under good growing conditions the plant also produces many fruits during the off-season. During the harvest attention must be paid to the ripe fruits' skin as it can be easily bruised and is highly perishable.<ref name="Lost" />

=== Cultivars for crop production === Horticultural scientists in South Africa and the USA (Florida and California) have selected and named several ''Carissa'' types that tend to produce fruits more reliably. The fruits are larger, have a good texture and contain fewer seeds. In California they selected Fancy (many large fruits with few seeds), Torrey Pines (good crop production and abundant pollen), Frank (good pollen supplier but low yield), Chelsey and Serena. In Florida Gifford is one of the best fruit bearers. In Africa ''C. haematocarpa'' is defined suitable for drier areas and ''C. bispinosa'' for higher altitudes.<ref name="Lost" />

== Environmental requirements == ''Carissa macrocarpa'' requires warm, moist subtropical climate. It tolerates different exposures as full sun and fairly heavy shade. As a coastal plant it can deal very well with salty ocean spray.

{| class="wikitable" |- ! Factor !! Description<ref name="Lost" /> |- | Rainfall || Up to 1000&nbsp;mm/a |- | Drought || Drought-resistant and no watering requirements during summer rainfall areas |- | Altitude || 1000 m a.s.l. (Eswatini); likely up to 1500 m. |- | Cold || Cold-tolerant to -5&nbsp;°C; young plants needs protection |- | Warmth || Up to 32&nbsp;°C in the shade (Pretoria); best growth in full sun exposure |- | Soil || Any (limestone, heavy clay, sand) if it drains well |- | Salinity || Salt-tolerant (5000 ppm) |}

== References == {{Commons}} {{Reflist}}

==External links== * [http://www.desert-tropicals.com/Plants/Apocynaceae/Carissa_macrocarpa.html Desert-Tropicals.com] {{Webarchive|url=https://web.archive.org/web/20160303181054/http://www.desert-tropicals.com/Plants/Apocynaceae/Carissa_macrocarpa.html |date=2016-03-03 }} * {{cite web|title=''Carissa macrocarpa''|work=PlantZAfrica.com|url=http://www.plantzafrica.com/plantcd/carismac.htm|access-date=2010-02-12|archive-date=2015-12-15|archive-url=https://web.archive.org/web/20151215072401/http://www.plantzafrica.com/plantcd/carismac.htm}} * {{cite web|title=''Carissa macrocarpa''|work=Ecocrop FAO|url=http://ecocrop.fao.org/ecocrop/srv/en/cropView?id=4229|access-date=2010-02-12|archive-url=https://web.archive.org/web/20120229191645/http://ecocrop.fao.org/ecocrop/srv/en/cropView?id=4229|archive-date=2012-02-29}} * [http://www.ispot.org.za/species_dictionary/Carissa%20macrocarpa Images on iSpot] * {{AfricanPlants|Carissa macrocarpa}}

{{Taxonbar|from=Q934636}}

macrocarpa Category:Flora of Southern Africa Category:Flora of South Tropical Africa Category:Flora of the Democratic Republic of the Congo Category:Flora of Kenya Category:Crops originating from South Africa Category:Fruits originating in Africa Category:Plants used in bonsai Category:Garden plants of Southern Africa